The Newest Threat: Arse Bombers

(CBS) Al Qaeda has developed a new tactic that allows suicide bombers to breach even the tightest security, as CBS News correspondent Sheila MacVicar reports.

Inside a Saudi palace, the scene was the bloody aftermath of an al Qaeda attack in August aimed at killing Prince Mohammed Bin Nayef, head of Saudi Arabia's counter terrorism operations.

To get his bomb into this room, Abdullah Asieri, one of Saudi Arabia's most wanted men, avoided detection by two sets of airport security including metal detectors and palace security. He spent 30 hours in the close company of the prince's own secret service agents - all without anyone suspecting a thing.

How did he do it?

Taking a trick from the narcotics trade - which has long smuggled drugs in body cavities - Asieri had a pound of high explosives, plus a detonator inserted in his rectum.

This was a meticulously planned operation with al Qaeda once again producing something new: this time, the Trojan bomber.

The blast left the prince lightly wounded - a failure as an assassination, but as an exercise in defeating security, it was perfect.

The bomber persuaded the prince he wanted to leave al Qaeda, setting a trap.

Al Qaeda has an animated movie showing the meeting between the bomber and the prince. Asieri says more senior al Qaeda figures want to surrender and convinces the prince to talk to them on a cell phone.

In the conversation recorded by al Qaeda, you hear a beep in the middle of two identical phrases that are repeated by the bomber and his handler.